Enhanced recording operation in an overdubbing device

ABSTRACT

A CPU of an overdubbing device plays back a music file recorded in a memory card of the device and outputs the file as a played-back audio signal while mixing the played-back audio signal with an external audio signal input from the outside, to thus perform overdubbing. A music file recorded through overdubbing last time is automatically set as a playback music file for the next time, and a selected state of means for selecting execution/nonexecution of overdubbing is maintained as the state of execution. As a result, overdubbing is enabled by twice operations of a record key, whereby the operation is made identical with operation performed during ordinary recording.

PRIORITY INFORMATION

This application claims priority to Japanese Patent Application No. 2008-005588 filed on Jan. 15, 2008 which is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an overdubbing device and, more particularly, to a device that plays back a recorded music file, to thus output a played-back audio signal, and that records the played-back audio signal while mixing it with an external audio signal input from the outside.

2. Related Art

There has hitherto been put forward an overdubbing apparatus that plays back a recorded music file, to thus output a played-back audio signal, and that records the played-back audio signal while mixing it with an external audio signal input from the outside.

For instance, JP 7-85593 A discloses an overdubbing function of reading audio data recorded in a recorder and writing mixed audio data back into the recorder by use of a buffer.

JP 2003-66999 A discloses an overdubbing function of mixing an audio signal input from a microphone with an MP3 audio signal of a source file in a memory card, storing a resultant mix as a mixed file in the memory card, and utilizing the mixed file as a new source file from the next time.

JP 2004-157260 A discloses an overdubbing function of repeating operation for mixing an input audio signal with a source file in a memory card, to thus create a first mixed file, and mixing the first mixed file taken as a new source file with an input audio signal, to thus create a second mixed file.

However, the related-art device encounters problems stemming from complication of operation, such as a necessity for operation for manually selecting a source music file (a source file) used when overdubbing is performed, a necessity for special key operation for performing overdubbing (e.g., a MIX key). In particular, when overdubbing is repeatedly performed, it is necessary to repeatedly perform the special operations; hence, complication becomes noticeable.

SUMMARY

The present invention provides a device that performs overdubbing by simple operation; particularly, a device that enables considerable enhancement of user's operability when overdubbing is repeatedly performed.

An overdubbing device of the present invention plays back a recorded music file, outputs a played-back audio signal, and records the played-back audio signal while mixing the played-back audio signal with an external audio signal input from the outside. The device of the present invention has a setting unit that sets a recorded music file as a playback music file for the next time; a selection unit that is a unit for selecting execution/nonexecution of overdubbing and that maintains a selected state of execution of overdubbing when overdubbing was performed last time; and a recording unit that plays back the playback music file in response to operation of a record key and a state of the selection unit, to thus perform overdubbing.

In an embodiment of the present invention, the overdubbing device has a normal recording mode for recording only the external audio signal input from the outside in addition to the overdubbing mode. The recording unit shifts to a record standby state by first operation of record key and performs recording by second operation of the record key in the normal recording mode; and shifts to a record standby state by the first operation of the record key and plays back the playback music file by second operation of the record key in the overdubbing mode, to thus perform overdubbing by the same operation as that performed in the normal recording mode.

According to the present invention, overdubbing is performed by simple operation. In particular, when overdubbing is repeatedly performed, user's operability can be significantly enhanced.

The invention will be more clearly comprehended by reference to the embodiment provided below. However, the following embodiment is a mere illustration, and the scope of the invention is not limited to the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described in detail by reference to the following drawings, wherein:

FIG. 1 is a block diagram showing the configuration of a portable overdubbing device of an embodiment;

FIG. 2 is a processing flowchart of the embodiment;

FIG. 3 is a view showing a screen display for selecting a file to be played back;

FIG. 4 is a view showing a playback screen display;

FIG. 5 is a view showing a screen for selecting whether or not to perform overdubbing;

FIG. 6 is a view showing a screen display appearing during overdubbing;

FIG. 7 is a view showing a playback screen display appearing at the end of overdubbing; and

FIG. 8 is a block diagram showing the internal configuration of a CPU.

DETAILED DESCRIPTION

An embodiment of the present invention will be described hereunder by reference to the drawings.

An overdubbing device of the present embodiment is a portable overdubbing device; specifically, a stereo overdubbing device having a built-in microphone. The portable overdubbing device has various operation keys. The operation keys include a record key (a REC key), a key for playing back a recorded music file (a PLAY key), a key for stopping recording/playing back operation (a STOP key), a menu key for activating a menu, a dial key for performing settings or changing, and others. Further, the portable overdubbing device has a display, such as an LCD and an organic EL, and displays various setting conditions and recording/playing-back conditions.

FIG. 1 shows a block diagram showing the configuration of a portable overdubbing device. A dial key 10, an LCD 12, an operation key 14 are provided on the front of the device. The dial key 10 is for selecting a music file to be played back and selecting whether or not to perform overdubbing. The operation key 14 includes the record key, the playback key, the stop key, and the menu key as mentioned previously. An operation signal from the dial key 10 and the operation key 14 is supplied to a CPU 18.

An audio signal from the outside is input to an input terminal (AUDIO IN) and supplied to a codec (CODEC) 16. The codec 16 converts the external audio signal into a digital signal, to thus encode the signal, and supplies the thus-encoded signal to the CPU 18. The CPU 18 writes the external audio signal data as a music file into a memory card 30 loaded in a card socket 28. The data may also be compressed as an MP3 file. The CPU 18 operates by means of a clock signal from a system clock 19 and performs signal processing by using RAM 20 as working memory in accordance with a program previously stored in ROM 22. In particular, the CPU 18 stores a state of execution/nonexecution of overdubbing in the RAM 20. In a default state achieved immediately after activation of power, there is a state of nonexecution of overdubbing, and a user operates the operation key 14, thereby arbitrarily selecting execution or nonexecution of overdubbing. The CPU 18 stores the currently-selected state in the RAM 20. The CPU 18 also reads a music file recorded in the memory card 30, expands the compressed music file, and supplies the file to the codec 16. The codec 16 decodes the music file, converts the thus-decoded file into an analog signal, and outputs the signal from an output terminal (AUDIO OUT). During overdubbing operation, a music file recorded in the memory card 30 is played back; mixed with an external audio signal, such as music of the guitar, vocals, and the like, input from the input terminal; and output as a music signal. The CPU 18 writes the thus-mixed music signal data as a music file into the memory card 30. When written into the memory card 30, the music file is imparted with a file name different from that of the played-back music file (a source file). FIG. 8 shows a functional block diagram of the CPU 18. The music file played back from the memory card 30 is stored in the buffer memory 29 and supplied to a mixing unit 18 a of the CPU 18. The mixing unit 18 a captures the external audio signal; adds the thus-captured signal to the played-back music signal; supplies the thus-added signal to the codec 16 and outputs as a music signal; stores the signal into the buffer memory 29; and further writes the signal into the memory card 30. In addition to including the mixing unit 18 a, the CPU 18 has a part cancellation unit 18 b for removing a specific signal included in the played-back music signal and a controller 18 c for controlling a playback speed achieved during playing-back and recording operation.

The respective units of the portable overdubbing device operate upon receipt of power supply from a battery 24. The battery 24 becomes recharged by means of power from a power circuit 26.

In such a configuration, the CPU 18 selectively performs recording (normal recording), overdubbing, and playback in accordance with operation of the operation key 14. However, when overdubbing is performed, a music file to be played back is first selected by operating the dial key 10; a selection as to whether or not to perform overdubbing is made; and the record key is operated. Thus, operations are intricate. Therefore, the CPU 18 of the present embodiment performs processing provided below to simplify user's operation required during overdubbing. First, when recording or overdubbing is performed, a recorded music file is automatically set as a music file for the next playback. When the music file is automatically set as a playback music file for the next time, the user does not need to select a music file (a source file) to be played back when the user performs overdubbing operation next time. “Automatic setting” means setting a default playback state for the music file or setting the music file in a playback standby state. The playback standby state means that a music file is automatically played back when a key is operated next time. Second, when overdubbing is performed, the state of execution/nonexecution of overdubbing is held, as it is, in the state of execution. Operability is considerably enhanced by performing these processing operations. Specifically, when overdubbing is repeated, a music file recorded by previous execution of overdubbing is automatically set as a playback music file, thereby saving the user from selecting a source file. Moreover, the state of execution of overdubbing is held as it is, which saves the user from again selecting execution of overdubbing. As a result of the efforts being saved, even when repeatedly performing overdubbing, the essential requirement for the user is to perform only the same operation as that performed during normal recording operation.

FIG. 2 shows a processing flowchart of the present embodiment. First, the user operates the dial key 10 to select a music file to be played back (S101). FIG. 3 shows an example playback file selection screen displayed on the LCD 12 by the CPU 18. The example is a case where four music files are recorded in the memory card 30. An “A.WAV” file among the four music files is highlighted, showing that the file is currently selected. When selection of a playback music file is completed, the CPU 18 then displays a playback screen on the LCD 12 (S102). FIG. 4 shows an example of a playback screen displayed on the LCD 12 by the CPU 18. The name of a file to be played back is displayed along with a time indication. The playback screen shows a file remaining in a playback standby state, and the drawing shows that the selected “A.WAV” file is in a playback standby state. When the record key (REC key) is operated in this state (first operation of the record key: S103), processing proceeds to a record standby state. The CPU 18 determines whether or not the dial key 10 is operated in the record standby state (S104). Overdubbing is set in a nonexecution mode in a default state achieved immediately after activation of power. At the time of first overdubbing, execution of overdubbing must be selected; hence, the user operates the dial key 10 to select execution of overdubbing. When execution of overdubbing is selected, the CPU 18 stores the state in the RAM 20 and maintains the state until a change is made to the current state (S105). FIG. 5 shows an example screen for selecting execution/nonexecution of overdubbing. Execution (ON)/nonexecution (OFF) of overdubbing (OVERDUB) is displayed, and execution is highlighted, to thus show that execution is currently selected.

When the user again operates the record key (REC key) in this state (second operation of the record key: S106), the CPU 18 determines whether the state of overdubbing is execution or nonexecution (S107). Since the state of overdubbing is stored in the RAM 20 and set to execution, a determination is made as YES, and overdubbing is commenced. Specifically, the CPU 18 reads the selected “A.WAV” file from the memory card 30; plays back the file; and outputs a played-back signal as a played-back music signal from an output terminal (S108). The played-back signal is mixed with an external audio signal by a mixing unit 18 a in the CPU 18. The thus-mixed music signal data are written in the memory card 30 as a music file with another file name; for instance, “X.WAV” (S109). FIG. 6 shows an example screen appearing during overdubbing operation. A file name of a music file (a source file) being played back and a file name of an overdubbed music file are displayed along with a time indication. Overdubbing is performed until the user operates the stop key. Nonexecution of overdubbing, which is the default state achieved immediately after activation of power, is kept unless the user operates the dial key 10. In S107, the CPU 18 determines that overdubbing is in a nonexecution state and only performs recording of the external audio signal without playing back the “A.WAV” file.

When the user operates the stop key (S110), the CPU 18 stops overdubbing operation and again displays the playback screen on the LCD 12 (S111). FIG. 7 shows an example playback screen. A file name of the music file “X.WAV” recorded in the memory card 30 by means of overdubbing is displayed, and the file is set in a playback standby state. It should be noted that the “X.WAV” file is set in a playback standby state in spite of the fact that the user did not perform operation for selecting a file. Processing pertaining to S103 and subsequent steps is repeated.

When the user operates the record key (REC key) in this state, the CPU 18 determines whether or not the dial key 10 is operated (S104). Since execution of overdubbing has already been selected by previous operation of the dial key 10 and the state is maintained, the user does not need to operate the dial key 10 when performing overdubbing again. When the user further operates the record key (REC key) in this state (S106), the CPU 18 again determines the state of execution/nonexecution of overdubbing (S107); makes a determination as YES; and starts playing back a music file (S108). The file played back at this time is the “X.WAV” file set in the playback standby state in S111.

In the meantime, when the user performs normal recording operation rather than overdubbing operation, the user operates the record Key, to thus shift the device to a record standby state. After confirming that overdubbing is set in a nonexecution state (the nonexecution state is selected by operating the dial key 10 when overdubbing is set in an execution state), the record key is again operated, to thus perform recording.

As mentioned above, at the time of first overdubbing, execution of overdubbing must be selected by operating the dial key 10. However, when overdubbing is repeatedly performed, the state of execution/nonexecution of overdubbing is maintained as-is; hence, the user does not need to operate the dial key 10 anew. Moreover, since the music file recorded through previous overdubbing is automatically set in the playback standby state, the user does not need to select the source file at the time of execution of overdubbing. As is seen from the flowchart shown in FIG. 2, operation to be performed when second or subsequent overdubbing operation is carried out includes only operation of the record key (REC key) performed in S103 and operation of the record key (REC key) performed in S106. These operations are totally identical with the operations performed during ordinary recording that is not overdubbing. Specifically, when repeatedly performing overdubbing, the user performs operations that are completely identical with those performed for ordinary recording operation. 

1. An overdubbing device comprising: a setting unit capable of selecting a playback audio file when an initial overdubbing operation is executed, the setting unit also automatically setting an overdubbed audio file as a playback audio file for a next overdubbing operation; a selection unit capable of selecting and maintaining an overdubbing execution state after the initial overdubbing operation is executed; and a recording unit that shifts to a record standby state in response to a first operation of a record key and plays back the playback audio file for overdubbing in response to a second operation of the record key when the overdubbing execution state is maintained by the selection unit, wherein the recording unit performs overdubbing repeatedly in accordance with the first operation and the second operation of the record key while the overdubbing execution state is maintained by the selection unit.
 2. The overdubbing device according to claim 1 comprising a normal recording mode and an overdubbing mode, wherein the recording unit is further capable of shifting to the record standby state by the first operation of the record key and performing recording by the second operation of the record key in the normal recording mode, the normal recording mode being capable of recording only an external audio signal input originating from outside the overdubbing device; the recording unit is further capable of shifting to the record standby state by the first operation of the record key and playing back the playback audio file by the second operation of the record key in the overdubbing mode; and overdubbing operations in the overdubbing mode are operationally identical to recording operations performed in the normal recording mode.
 3. The overdubbing device according to claim 2, wherein the selection unit is capable of selecting and maintaining the overdubbing execution state when a first overdubbing operation has already been performed in the overdubbing mode, and shifts an operation mode to the normal recording mode when nonexecution of overdubbing is selected before the second operation of the record key is performed.
 4. A method comprising: selecting an audio file for use during a first overdubbing operation in an overdubbing device; setting an overdubbing operation state; automatically setting an overdubbed audio file as an audio file for use during a second overdubbing operation; shifting to a record standby state in accordance with a first operation of a record key; and confirming setting of the overdubbing operation state and playing back the audio file for use during the second overdubbing operation in response to a second operation of the record key, the second overdubbing operation being identical to an operation in a normal recording mode of the overdubbing device. 